Design and Implementation of a Secure Company Network System

Abstract

This project presents the design and full implementation of an enterprise-grade secure company network system simulated in Cisco Packet Tracer. The network follows a three-tier hierarchical architecture comprising the Edge/Internet, Firewall, Distribution, and Access layers. High availability is achieved through dual Cisco ASA 5506-X firewalls in a cross connected topology, two Multilayer Switches (ML-SW1 and ML-SW2) running OSPF dynamic routing, HSRP for gateway redundancy, and LACP-based EtherChannel link aggregation. A Demilitarized Zone (DMZ) hosts Web, FTP, Email, and Storage servers, isolated from the internal network by the firewall. The internal network is segmented into five VLANs: Management (VLAN 10), LAN (VLAN 20), WLAN (VLAN 50), VoIP (VLAN 70), and Inside Servers (VLAN 90). A Wireless LAN Controller (WLC) manages access points across three office floors. RADIUS-based AAA authentication controls network access, while DHCP and DNS servers provide automatic addressing and name resolution. All configurations have been verified using Cisco IOS CLI commands.